Knife with detachable blade



Apnl w. E. NICKERSON KNIFE WITH DETACHABLE BLADE Filed May 22, 1924 m 8. Misha-:0-

Patented Apr. 19,1927.

UNITED STATES PATENT FFICE.

WILLIAM E. NICKEBSON, OF BOSTON, MASSACHUSETTS, ASSIGNOB TO GILLETTE SAFETY RAZOR COMPANY, 0;? BOSTON, MASSACHUSETTS, A CORPORATION OF :onnawaia-n.

Application filed llllay 22,

My invention relates to knives of the type in which the blade is readily detachable from the handle, so that after a blade has become unfit for further use it can be removed and replaced by another. My invention is intended to provide an improved knife of this character which will be particularly adapted for use in performing surgical operations, and resides in certain features of which the preferred construction is hereinafter described in connection with the accon'ipanying drawing, in whichl igure l is a side elevation of a surgical knife made in accordance with my invention, ready for use;

l igure 2 is a side elevation, partly in section, showing the blade-holding portion of the knife with the blade-clamping jaws open;

l igure 3 is aside elevation of a. blade adapted for use in the blade holder illus trated in Figures 1 and 2;

Figure l is a transverse section on the line 4- 4 in Figure 1; and c Figure 5 shows the front end of the blade holder in longitudinal section, with the jaws closed and the blade held between them.

The blade-holding portion :2 of the knife illustrated comprises two jaws, of which the upper jaw is integral with the handle and the lower jaw 3 is conneetedat its rear end thereto by means of apivot 4, so ,thatthe ilront ends of the awe can be separated for the insertion or removal of the blade 5, shown separately in Figure 3. The blade has acutting edge 6 and an elongated shank Tt-thich tapers rearwardly and is adapted to be grasped by the jaws of the blade holder, each jaw being provided with a longitudinal groove 8 to receive the corresponding edge t1? the blank shank and the parts are so pro 'iortioncd that when the blade is inserted in the holder, ready for use, the entire length of the cutting edge 6 is exposed in "front of the lower jaw 3. In order to hold the b ladeimmovable with respect to the holder in the direction of its length I provide one of the jawsof the holder, for example the lower jaw 23, with a recess 9 adapted to receive and fit a corresponding enlargement 10 at the rear end ofithe blade, and-for holdin the jaws closed I employ a sleeve 11 adapted'to slide on the front portion of the handle and to embrace the jaws KNIFE WITH DETACI-IABLE BLADE.

1924. l Serial No. 715,222.

tional engagement therewith.

The rearward movement of the sleeve 11 on the handle is limited by a suitable stop, such as 'a pin 12 passing transversely througl'i the handle in such position that when the sleeve is in contact with it the jaws are free to open, and preferably the upper and lower edges of the sleeve are smooth while its sides are corrugatedor otherwise roughened externally, as indicated at 13, for the purpose of ei'iabling the user to grip the sleeve firmly between the thumb and forefinger when forcing it toward the blade. The location of the corrugated surfaces on the sides of the sleeve, leaving its top and bottom smooth, hasjtheadvantage that the user is thereby led to grip the sleeve by its sides when operating it, so that if histhumb or finger slips it is not lil; 1y to come in contact with'thecutting'edge of the blade. I also prefer to"connect the lower jaw 23 to the pivots by givingythe rear .end of the jaw the shape of a hook let, as shown in Figure L so that t-he jaw is swung downward sufficiently it can be detached from the handle 2 by disengaging the hook ll from the pivot 4l,whereupon the sleeve 11 an be reniovedlby sliding has the front endof the upper jaw. l

The pai'ttsabove described are assembled by first pass ng the upper aw throughthe sleeve 11 and sliding the latter backward against ,the stop 12, ,then' engaging-the IOU release the blade shank, whereupon the parts of the handle may be taken apart if desired, as above explained.

It will be apparent from the foregoing description that when the blade is clamped between the jaws it will not only be held immovable but will be rendered practically as rigid as the handle itself by reason of the stiii'eniu g effect of the grooved jaws in which the edge portions of the blade shank are held, that by manipulating the sleeve and jaws the blade can be removed without touching it, and that all lheparts can be readily separated and put together, and thoroughly sterilized while disassembled, all of these characteristics being important in the use of surgical knives. The specific form of blade illui-ztrated is of course to be regarded merely as one example of a surgical blade. and in practice a set of blades of various sizes and having cutting edges of various contours will be provided with each handle and adapted for individual use therein. The details of construction of the holder, as well as the shape of the blade itself, may evidently be modified considerably without departing from my invention particularly in respect to the shape and arrangement of the blade-clan'iping jaws and the means employed for holding them together and positioning a blade between them.

I claim:

1. In a knife of the character described, the combination of a blade having an elongated shank, and a blade holder comprising a handle provided at its front end with an integral upper jaw having in its under edge a longitudinal groove adapted to receive the greater part of the upper edge of the blade and give lateral rigidity thereto, a lower jaw hinged at its rear end to the handle, and a clamping sleeve adapted to slide on the jaws in front of the handle, the outer edges of the jaws being provided with cam surfaces adapted to be engaged by the sleeve and to limit its clamping movement, whereby the jaws are caused to grip the blade firmly between them.

2. In a knife of the character described, the combination of a blade having an elongated shank, and a blade holder comprising a handle provided at its front end with an integral upper jaw having in its under edge a longitudinal groove adapted to receive the upper edge of the blade, a lower jaw hinged at its rear end to the handle and detachable therefrom when open, and a clamping sleeve adapted to slide on the jaws and to engage cam surfaces on their outer edges when moved forward thereon, whereby they are caused to grip the blade between them, said sleeve being removable from the upper jaw after the lower jaw has been detached.

3. In a knife of the character described, the combination of a blade having a rearwardly-tapering shank and an enlargement at the rear end of the shank, and a blade holder comprising a handle provided at its front end with an integral upper jaw having in its under edge a longitudinal groove adapted to receive the upper edge of the blade, a lower jaw hinged at its rear end to the handle and provided with a recess adapted to receive the enlargement on the blade shank, and a clamping sleeve adapted to slide on the jaws in front of the handle, the outer edges of said jaws being provided with cam surfaces adapted to be engaged by the sleeve and to limit its forward movement, whereby they are caused to grip the blade firmly between them.

4. In a knife of the character described, a blade holder comprising a handle provided at its front end with an integral upper jaw having a longitudinal groove in its under edge, a lower jaw hinged at its rear end to the front end of the handle and detachable therefrom when open, and a clamping sleeve adapted to slide on the jaws and to move rearward on the handle to a position behind the hinge of the lower jaw, the outer edges of said jaws being provided with ram surfaces adapted to be engaged by the sleevr on its forward movement and the sleeve being removable over the upper jaw after the lower jaw has been detached.

5. In a knife of the character described, a blade holder comprising a handle provided at its front end with an integral upper jaw having a longitudinal groove in its under edge, a lower jaw hinged at its rear end to the front end of the handle and provided in its upper edge with a longitudinal groove and a recess at the rear end of said groove, and a clamping sleeve adapted to slide on the jaws and to move rearward on the handle to a position behind the hinge of the lower jaw, the outer edges of said jaws being provided with cam surfaces adapted to be engaged by the sleeve and to limit its forward movement.

6. In a knife of the character described, a blade holder comprising a handle provided at its front end with an integral upper jaw having a longitudinal groove in its under edge, a lower jaw hinged at its rear end to the front end of the handle, and a claniping sleeve adapted to slide on the jaws and to engage cam surfaces on their outer edges when moved forward thereon, said sleeve be ing provided externally with smooth upper and lower edges and with roughened side surfaces.

Signed at Boston, Mass, this 19th day of May, 1924.

IVILLIAM E. NICKERSON. 

